1. Field of the Invention
The present invention is generally directed to a method and apparatus for sorting material and, more particularly, to a method for and sample selecting apparatus which automatically and continuously abstracts preselected ones of multiple samples for subsequent analysis about a single collection means.
2. Description of the Prior Art
It is common practice in the mining industry, for instance, to take samples of suspension of solids in water or the like for purposes of analyzing the constituency thereof. Various heretofore known prior art devices exist for basically providing a proper sample presentation to an on-stream analyzer wherein the samples to be selected and analyzed are periodically withdrawn from slurry streams.
One such known on-stream sampling and analyzing device suffers from several rather significant shortcomings. For example, this particular device employs electro-pneumatically operated sample cutters. Such sample cutters are ordinarily positioned under each of the flowing slurry streams. In practice, the correct positioning of such cutters is a very critical factor in order to have them properly operate, especially from the standpoint of providing a representative sample. Consequently, much time and effort are required to insure this rather precise positioning. Moreover, the electrical contacts normally associated with the cutter shaft present continuous operational problems.
As indicated, such known type of sample selector apparatus employs electro-pneumatic mechanisms. These mechanisms normally utilize the surrounding ambient air for the successful operation thereof. It may happen, however, that the ambient air surrounding such sample selector apparatus is subject to freezing and extreme weather conditions, and as a result thereof, the pneumatic mechanisms tend to lose some air. In effect, the cold air adversely affects the pneumatic mechanisms to the extent that they tend to step out of phase with a computer operatively associated therewith for controlling the same. Consequently, loss of assay ability during this period results. Obviously, such condition contributes to inaccuracies in sample read-outs.
In addition to the foregoing mentioned shortcomings prevalent with the above-noted type of sample selector apparatus, there is an added shortcoming in that such sample selector is totally enclosed. By virtue of this enclosure, detection of mechanism problems with the equipment and components are substantially prevented. Since the sample selector apparatus is totally enclosed, it is also virtually difficult to detect any sample problems, such as with flow volume or sample contamination. Furthermore, this particular selector apparatus is rather complicated in construction and, as a result thereof, repairs are somewhat costly and rather frequently required. Accordingly, it will be appreciated that with a greater frequency of repair there is a corresponding increase in apparatus downtime. Hence, a less efficient and economic operation results.
Difficulties are also encountered by reason of the fact that, if failure of one of the slurry units occurs, such failure adversely affects sample positions at other slurry units. Another debilitating factor which is associated with such aforenoted types of sampling apparatus is the contamination which may result whenever multiple samples are taken and presented to an on-stream analyzer. Consequently, of course, the sample readouts provided are not as accurate as otherwise would be desired and required.